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Fundamental and Applied Toxicology :... Feb 1984A long-term study was conducted to determine the possible chronic toxicity and oncogenicity of methylene chloride. Rats and hamsters were exposed by inhalation to 0,...
A long-term study was conducted to determine the possible chronic toxicity and oncogenicity of methylene chloride. Rats and hamsters were exposed by inhalation to 0, 500, 1500, or 3500 ppm of methylene chloride for 6 hr per day, 5 days a week, for 2 years. No exposure-related cytogenetic effects were present in male or female rats exposed to 500, 1500, or 3500 ppm. Females rats exposed to 3500 ppm had an increased mortality rate while female hamsters exposed to 1500 or 3500 ppm had decreased mortality rates. Carboxyhemoglobin values were elevated in rats and hamsters exposed to 500, 1500, or 3500 ppm with the percentage increase in hamsters greater than in rats. Minimal histopathologic effects were present in the livers of rats exposed to 500, 1500, or 3500 ppm. Decreased amyloidosis was observed in the liver and other organs in hamsters exposed to 500, 1500 or 3500 ppm. While the number of female rats with a benign tumor was not increased, the total number of benign mammary tumors was increased in female rats in an exposure-related manner. This effect was also evident in male rats in the 1500- and 3500-ppm exposure groups. Finally, male rats exposed to 1500 or 3500 ppm had an increased number of sarcomas in the ventral neck region located in or around the salivary glands. Therefore, in this 2-year study, some effects were observed in male and female rats exposed to 500, 1500, or 3500 ppm of methylene chloride. In contrast, hamsters exposed to the same exposure concentrations had less extensive spontaneous geriatric changes, decreased mortality (females), and lacked evidence of definite target organ toxicity.
Topics: Adenofibroma; Amyloid; Animals; Carboxyhemoglobin; Cricetinae; Female; Hydrocarbons, Chlorinated; Liver; Male; Mammary Neoplasms, Experimental; Mesocricetus; Methylene Chloride; Neoplasms, Experimental; Rats; Rats, Inbred Strains; Respiration; Salivary Gland Neoplasms; Sarcoma, Experimental; Time Factors
PubMed: 6693002
DOI: 10.1016/0272-0590(84)90217-3 -
International Journal of Environmental... Aug 2011Dichloromethane (methylene chloride) is a widely used chlorinated solvent. We review the available epidemiology studies (five cohort studies, 13 case-control studies,... (Review)
Review
Dichloromethane (methylene chloride) is a widely used chlorinated solvent. We review the available epidemiology studies (five cohort studies, 13 case-control studies, including seven of hematopoietic cancers), focusing on specific cancer sites. There was little indication of an increased risk of lung cancer in the cohort studies (standardized mortality ratios ranging from 0.46 to 1.21). These cohorts are relatively small, and variable effects (e.g., point estimates ranging from 0.5 to 2.0) were seen for the rarer forms of cancers such as brain cancer and specific hematopoietic cancers. Three large population-based case-control studies of incident non-Hodgkin lymphoma in Europe and the United States observed odds ratios between 1.5 and 2.2 with dichloromethane exposure (ever exposed or highest category of exposure), with higher risk seen in specific subsets of disease. More limited indications of associations with brain cancer, breast cancer, and liver and biliary cancer were also seen in this collection of studies. Existing cohort studies, given their size and uneven exposure information, are unlikely to resolve questions of cancer risks and dichloromethane exposure. More promising approaches are population-based case-control studies of incident disease, and the combination of data from such studies, with robust exposure assessments that include detailed occupational information and exposure assignment based on industry-wide surveys or direct exposure measurements.
Topics: Adult; Case-Control Studies; Cohort Studies; Europe; Female; Humans; Male; Methylene Chloride; Neoplasms; Occupational Exposure; Quebec; Risk Factors; Solvents; United States
PubMed: 21909313
DOI: 10.3390/ijerph8083380 -
BMC Complementary Medicine and Therapies Oct 2021Microbial resistance, diabetes mellitus, and obesity are global health care problems that have posed a serious threat to both human and environmental ecosystems. The...
BACKGROUND
Microbial resistance, diabetes mellitus, and obesity are global health care problems that have posed a serious threat to both human and environmental ecosystems. The goals of the present investigations are to investigate the phytoconstituents, antilipase, anti-α-amylase, and antimicrobial activity of Orobanche aegyptiaca Pers. (OA) from Palestine.
METHODS
Identification of the phytoconstituents of OA plant petroleum ether, methylene chloride, chloroform, acetone, and methanol extracts were conducted using pharmacopeia's methods, while porcine pancreatic lipase and α-amylase inhibitory activities were examined using p-nitrophenyl butyrate and 3,5-dinitro salicylic acid methods, respectively. Moreover, the antimicrobial activity was evaluated utilizing broth microdilution assay against eight bacterial and fungal strains.
RESULTS
The phytochemical screening results showed that the methanol extract of the OA plant is rich in phytochemical components, also this extract has powerful antilipase potential with an IC value of 19.49 ± 0.16 μg/ml comparing with the positive control (Orlistat) which has antilipase activity with IC value of 12.3 ± 0.35 μg/ml. Moreover, the methanol and chloroform extracts have powerful α-amylase inhibitory activity with IC values of 28.18 ± 0.22 and 28.18 ± 1.22 μg/ml, respectively comparing with Acarbose which has α-amylase inhibitory activity with IC dose of 26.3.18 ± 0.28 μg/ml. The antibacterial results showed that the methylene chloride extract exhibited the highest antibacterial activity among the other OA plant extracts with a MIC value of 0.78 mg/ml against S. aureus, while, the methylene chloride, petroleum ether, and chloroform extracts of the OA plant showed potential antifungal activity against C. albicans strains with MIC value of 0.78 mg/ml.
CONCLUSION
The OA methanol and chloroform extracts could be excellent candidates as antilipase and anti-α-amylase bioactive materials. In addition, methylene chloride, petroleum ether, and chloroform extracts could be potential natural antimicrobial products.
Topics: Animals; Anti-Infective Agents; Anti-Obesity Agents; Humans; Hypoglycemic Agents; Lipase; Microbial Sensitivity Tests; Middle East; Orobanche; Phytochemicals; Swine; alpha-Amylases
PubMed: 34625075
DOI: 10.1186/s12906-021-03431-x -
Clinical Hypertension 2014The present study was designed to examine whether methylene chloride (CH2Cl2) fraction extracted from Rubus coreanum affects the contractility of the isolated thoracic...
INTRODUCTION
The present study was designed to examine whether methylene chloride (CH2Cl2) fraction extracted from Rubus coreanum affects the contractility of the isolated thoracic aortic strips and blood pressure of normotensive rats.
METHODS
One of the common carotid arteries or of the femoral arteries was catheterized with a polyethylene tubing. The tubing was connected to a pressure transducer, and pulse of the mean arterial blood pressure was recorded on a biological polygraph continuously.
RESULTS
The CH2Cl2 fraction (range, 200 to 800 μg/mL) significantly depressed both phenylephrine (PE, 10 μM)- and high K(+) (56 mM)-induced contractile responses of the isolated thoracic aortic strips in a concentration-dependent fashion. In the simultaneous presence of N(ω)-nitro-L-arginine methyl ester hydrochloride (L-NAME) (an inhibitor of nitric oxide [NO] synthase, 300 μM) and the CH2Cl2 fraction (400 μg/mL), both PE- and high K(+)-induced contractile responses were recovered to the significant level of the corresponding control response in comparison with inhibition of CH2Cl2 fraction treatment alone. Moreover, in the simultaneous presence of the CH2Cl2 fraction after pretreatment with 0.4% CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propane sulfonate), both PE- and high K(+)-induced contractile responses were recovered to the significant level of the corresponding control response compared to the inhibitory response of CH2Cl2 fraction treatment alone. Also, in anesthetized rats, the CH2Cl2 fraction (range, 0.3 to 3.0 mg/kg) injected into a femoral vein dose-dependently produced depressor responses. This hypotensive action of the CH2Cl2 fraction was greatly inhibited after treatment with phentolamine (1 mg/kg), chlorisondamine (1 mg/kg), L-NAME (3 mg/kg/30 min), or sodium nitroprusside (30 μg/kg/30 min). Intravenous infusion of the CH2Cl2 fraction (range, 1.0 to 10.0 mg/kg/30 min) markedly inhibited norepinephrine-induced pressor responses.
DISCUSSION
Taken together, these results demonstrate that the CH2Cl2 fraction causes vascular relaxation in the isolated rat thoracic aortic strips as well as hypotensive action in anesthetized rats. These vasorelaxation and hypotension of the CH2Cl2 fraction seem to be mediated at least by the increased NO production through the activation of NO synthase of the vascular endothelium and the inhibitory adrenergic modulation.
PubMed: 26893911
DOI: 10.1186/s40885-014-0006-1 -
ACS Omega Dec 2022Amphiphilic aryl radicals generated upon visible light irradiation of arylazo sulfones have been exploited in the development of a solventylation strategy via hydrogen...
Amphiphilic aryl radicals generated upon visible light irradiation of arylazo sulfones have been exploited in the development of a solventylation strategy via hydrogen atom transfer (HAT). The present protocol succeeded in the versatile functionalization of various olefins with carbon-centered radicals deriving from acetone, acetonitrile, chloroform, methylene chloride, nitromethane, methyl acetate, and methyl formate under metal- and photocatalyst-free conditions. The direct addition of the aryl radicals onto the olefin substrates was suppressed under high dilution conditions.
PubMed: 36591128
DOI: 10.1021/acsomega.2c07172 -
Animals : An Open Access Journal From... Oct 2023Besides living as a free-ranging primate in the horn of Africa and the Arabian Peninsula, the hamadryas baboon has an important place in zoos and can be found in...
Besides living as a free-ranging primate in the horn of Africa and the Arabian Peninsula, the hamadryas baboon has an important place in zoos and can be found in biomedical research centers worldwide. To be valuable as a non-human primate laboratory model for man, its anatomy should be portrayed in detail, allowing for the correct interpretation and translation of obtained research results. Reviewing the literature on the use of the baboon in biomedical research revealed that very limited anatomical works on this species are available. Anatomical atlases are incomplete, use archaic nomenclature and fail to provide high-definition color photographs. Therefore, the skeletons of two male hamadryas baboons were prepared by manually removing as much soft tissues as possible followed by maceration in warm water to which enzyme-containing washing powder was added. The bones were bleached with hydrogen peroxide and degreased by means of methylene chloride. Photographs of the various bones were taken, and the anatomical structures were identified using the latest version of the Nomina Anatomica Veterinaria. As such, the present article shows 31 annotated multipanel figures. The skeleton of the hamadryas baboon generally parallels the human skeleton, but some remarkable differences have been noticed. If these are taken into consideration when evaluating the results of experiments using the hamadryas baboon, justified conclusions can be drawn.
PubMed: 37835730
DOI: 10.3390/ani13193124 -
Scandinavian Journal of Work,... Jun 1975The accumulation of methylene chloride and its metabolites in different organs and tissues was studied in an experimental series comprising 10 rats. Each rat was exposed...
The accumulation of methylene chloride and its metabolites in different organs and tissues was studied in an experimental series comprising 10 rats. Each rat was exposed for 1 h to radioactive methylene chloride (14C) in a concentration amounting to 1,935 mg/m3 in inspiratory air. Radioactive carbon atoms were found in the isolated carbon monoxide after exposure. There was also a close correlation between the activity of carbon monoxide extracted from the blood sample and the amount of carboxyhemoglobin (COHb) in the specimen. The largest concentration of methylene chloride and its metabolites per gram of tissue was found in white adipose tissue. This concentration had declined by more than 90% 2 h after exposure, whereas the concentration in the liver declined by about 25% during the same period. The amount accumulated in the brain displayed a decline of about 75% 2 h after exposure. Thus the examination showed that the increased concentration of COHb in the blood during exposure to methylene chloride is due to the metabolism of methylene chloride into carbon monoxide.
Topics: Adipose Tissue; Animals; Carbon Monoxide; Carbon Radioisotopes; Carboxyhemoglobin; Environmental Exposure; Hydrocarbons, Chlorinated; Male; Methylene Chloride; Rats; Time Factors
PubMed: 1226505
DOI: 10.5271/sjweh.2856 -
Regulatory Toxicology and Pharmacology... Mar 2021Dichloromethane (DCM) is a high production volume chemical (>1000 t/a) mainly used as an industrial solvent. Carcinogenicity studies in rats, mice and hamsters have... (Review)
Review
Dichloromethane (DCM) is a high production volume chemical (>1000 t/a) mainly used as an industrial solvent. Carcinogenicity studies in rats, mice and hamsters have demonstrated a malignant tumor inducing potential of DCM only in the mouse (lung and liver) at 1000-4000 ppm whereas human data do not support a conclusion of cancer risk. Based on this, DCM has been classified as a cat. 2 carcinogen. Dose-dependent toxicokinetics of DCM suggest that DCM is a threshold carcinogen in mice, initiating carcinogenicity via the low affinity/high capacity GSTT1 pathway; a biotransformation pathway that becomes relevant only at high exposure concentrations. Rats and hamsters have very low activities of this DCM-metabolizing GST and humans have even lower activities of this enzyme. Based on the induction of specific tumors selectively in the mouse, the dose- and species-specific toxicokinetics in this species, and the absence of a malignant tumor response by DCM in rats and hamsters having a closer relationship to DCM toxicokinetics in humans and thus being a more relevant animal model, the current classification of DCM as human carcinogen cat. 2 remains appropriate.
Topics: Administration, Inhalation; Animals; Biotransformation; Carcinogens; Cricetinae; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Evaluation, Preclinical; Humans; Methylene Chloride; Mice; Rats; Species Specificity
PubMed: 33387565
DOI: 10.1016/j.yrtph.2020.104858 -
Journal of Traditional Chinese Medicine... Aug 2022To evaluate Sterculia diversifolia stem bark and leaves for phytotoxic, genotoxic and enzymes inhibition potential.
OBJECTIVE
To evaluate Sterculia diversifolia stem bark and leaves for phytotoxic, genotoxic and enzymes inhibition potential.
METHODS
Phytotoxic activity of both stem bark and leaves were screened using Lemna minor. The genotoxic activity of Sterculia diversifolia stem bark and leaves extracts were tested using comet assay protocol while enzyme inhibition activity of crude extract and various fractions of both stem bark and leaves were evaluated using acetyl cholinesterase, lipoxygenase, β-glu-curonidase, urease, xanthine oxidase and carbonic anhydrase.
RESULTS
Phytotoxic activity showed significant results in dose dependant manner in both stem bark (ethyl acetate and n-butanol) and leaves (ethyl acetate, n-butanol and n-hexane) fractions. In genotoxic activity, dichloromethane fraction showed significant activity followed by ethyl acetate fraction. Acetyl cholinesterease inhibitory activity showed significant results in both stem bark and leaves fractions, while significant lipoxygenase inhibition was shown by ethyl acetate, dichloromethane, crude extract and n-hexane fractions of both stem bark and leaves. β-glucuronidase, urease and carbonic anhydrase inhibitory activity showed highly significant results in ethyl acetate fraction of both stem bark and leaves, while xanthine oxidase inhibition was shown by dichloromethane fraction of stem bark and leaves extracts.
CONCLUSIONS
This study emphasizes the important phytotoxic, genotoxic and enzyme inhibition effects of Sterculia diversifolia stem bark and leaves. Hence, it is clear that Sterculia diversifolia stem bark and leaves possess phytotoxic, genotoxic and enzyme inhibitory agents.
Topics: 1-Butanol; Alkaloids; Carbonic Anhydrases; DNA Damage; Humans; Lipoxygenases; Methylene Chloride; Plant Bark; Plant Extracts; Plant Leaves; Urease; Xanthine Oxidase
PubMed: 35848976
DOI: 10.19852/j.cnki.jtcm.2022.04.005 -
Zeitschrift Fur Naturforschung. C,... 2013Chromatographic investigation of the methylene chloride/methanol extract of the aerial parts of Artemisia herba-alba afforded a new monoterpene dimer, in addition to a...
Chromatographic investigation of the methylene chloride/methanol extract of the aerial parts of Artemisia herba-alba afforded a new monoterpene dimer, in addition to a known monoterpene and three known sesquiterpene lactones. The structures of the compounds were determined by comprehensive NMR analyses, including DEPT, COSY, HMQC, HMBC, and HRMS.
Topics: Artemisia; Magnetic Resonance Spectroscopy; Spectrometry, Mass, Electrospray Ionization; Terpenes
PubMed: 24459767
DOI: 10.1515/znc-2013-9-1001